Mesonephric adenocarcinoma of the uterine corpus

Abstract

Mesonephric carcinomas are rare in the female genital tract and usually are found in sites where embryonic remnants of wolffian ducts are usually detected, such as the uterine cervix, broad ligament, mesosalpinx and exceptionally rarely in the uterine corpus. To date, only four cases of mesonephric carcinomas arising in the uterine corpus have been described in literature. Here we report two cases of mesonephric carcinomas arising in a deep intramural location of the uterine corpus in a 55-year-old woman and a 62-year-old woman in Chinese populations. It is believed to be the first report in China. Both cases presented with a little postmenopausal bleeding. Before hospitalized, uterine curettages were programmed for both cases. The pathology reports were mesonephric adenocarcinoma. A total hysterectomy and bilateral salpingo-oophorectomy were performed. On gross examination, the tumors of both cases were confined to the myometrium. Microscopic examination found both tumors of these two cases were adenocarcinomas mixed with spindle cell component. The most primary histologic patterns of the mesonephric adenocarcinomas were tubular glands that varied in size and were lined by one to several layers of columnar cells. Immunohistochemically, the tumor cells expressed positive with CD10, calretinin, vimentin, cytokeratin (AE1/AE3) and epithelial membrane antigen (EMA); but expressions of ER and PR were completely negative. The peculiar location of mesonephric carcinoma of the uterine corpus may be misinterpreted as other histological type neoplasms. Awareness of this rare phenomenon and immunostaining for markers of mesonephric carcinoma can prevent from making a false diagnosis.

Keywords: Mesonephric carcinoma; histologic patterns; immunohistochemistry; uterine corpus.

Figure 1

Gross image of the first case: a mass was located in the lower 1/3 portion lateral wall of the uterus to endocervix (A) with the sectioned surface of the mass (B).

Figure 2

Gross image of the second case: a mass was located in the higher 2/3 portion of the uterus (A), with sectioned surface of the mass (B).

Figure 3

The most helpful histological pattern for diagnosis consists of large sheets of closely packed small round tubules, often with dense intraluminal eosinophilic secretions (A). With magnification of A, nuclear divisions can be seen (B). Sheets of spindle cells component are adjacent to the ductal pattern (C). Sex cord pattern are present (D). A sarcomatoid component consists of nonspecific malignant spindled cells (E). Mesonephric adenocarcinoma extensively infiltrates wall of uterus without any infiltration of cervical mucosa (F). (A × 100, B × 200, C × 100, D × 40, E × 40, F × 40).

Figure 4

Immunohistochemical expression profiling of mesonephric adenocarcinomas. The tumor cells are positive for CD10 (A) Calretinin (B) but negative for ER (C) and PR (D) and also positive for cytokeratin (AE1/AE3) (E). A small part of tumor cells express vimentin (F). (A × 100, B × 40, C × 100, D × 100, E × 40, F × 100).